Method of making web with partially embedded fibers

ABSTRACT

A method of making an adhesive backed web, wherein the adhesive layer of such web has partially embedded filaments projecting therefrom. The filaments may comprise a thermoplastic material or a hot melt adhesive. The filaments are contacted to a major surface of a liner material then pressed partially thereinto. An adhesive layer, as from an adhesive backed film, is then laminated to the filament-containing liner, allowing the adhesive layer to pick up the filaments.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. 371 ofPCT/US2016/039964, filed Jul. 29, 2016, which claims the benefit of U.S.Provisional Application No. 62/198,962, filed Jul. 30, 2015, thedisclosure of which is incorporated by reference in its/their entiretyherein.

BACKGROUND

Pressure sensitive adhesives are useful for the joining of twomaterials. The interfaces between the adhesive and the materials arevital to the performance of the joined materials. The loss of adhesionat either interface may result in failure of the materials.

One example of an adhesion interface requiring peak performance is adurable film displaying image graphics adhered to substrates, where thefilm is a backing material upon which an adhesive layer is added foradhesion to the substrate. Adhesion of a large image graphic film tosubstrates encounters the problem of entrapped air between the film andthe substrate. Anyone who has ever attempted to hang wallpaper canappreciate the frustration that can arise when entrapped air beneath anadhesive-backed film cannot be removed easily. The most common solutionsto this problem are to remove and re-apply the film or to perforate thefilm to release the entrapped air. Multiple attempts to adhere the samefilm to a substrate can compromise the pressure sensitive adhesive orincrease the probability of uneven or misaligned film on the substrate.Perforating a film mars its appearance. The removal of air bubbles isalso labor intensive.

Prior approaches have addressed facile adhesion of image graphics filmto substrate by concentrating on specialized topographical constructionsof the pressure sensitive adhesive, often by coating the adhesive onto astructured release liner and thereby allowing the structure of therelease liner to imprint into the adhesive layer. To this end, varioustechnologies have been developed to manufacture such release liners.See, for e.g., U.S. Pat. No. 5,897,930 “Multiple Embossed Webs”(Calhoun, et. al), and U.S. Pat. No. “Adhesive Having a MicroreplicatedTopography and Methods of Making and Using the Same” (Sher et. al.).

Another approach to topographical adhesives is the formation of ridgesor recesses in a release or transfer liner to generate a temporarytopography on the adhesive. For example, British Patent Specification1,511,060 discloses a heat- and pressure sensitive adhesive on animpermeable backing that is formed by application of heat and pressureand a release liner having a specific topography or by coating theadhesive onto the release liner, whereupon the release liner is removed.Then, bonding of the adhesive to the desired substrate also requires astep of heat and pressure that adheres the adhesive layer to thesubstrate. This step is also required to improve the appearance of thefinal product. This complicated procedure of generating the adhesion ofthe layer to the backing and then generating the adhesion to the finalsubstrate minimizes utility of the construction for use in large formatgraphics and other industrial requirements. Furthermore, the depth ofthe recesses used to create an effective temporary topography on thenontacky adhesive surface is at least 45 μm, and then only if the widthof the recesses is at least 130 μm.

Another example of a temporary topography formed on an adhesive surfaceis disclosed in U.S. Pat. Nos. 5,344,681 and 5,449,540 (both Calhoun etal.). A segmented pressure-sensitive adhesive transfer tape is designedto prevent lateral flow of the adhesive prior to transfer but allowsflow after transfer to form a continuous adhesive bond. The smalladhesive segments have controllable thickness. An adhesive transfer tapecomprises: a carrier with two opposed surfaces with one containing aseries of recesses and the other being relatively smooth; a pressuresensitive adhesive being present in the recesses which are surrounded byan adhesive free area such that when the tape is wound about itself withthe surfaces contacting and then unwound, adhesive transfers from theone surface to the other. Preferably, the recesses are formed byembossing and are in spaced-apart relationship. Preferably, they areoval, circular, polygonal or rectangular in cross section. Preferably,the adhesive is acrylic or rubber resin, pressure sensitive.

Another example of a temporary topography formed on an adhesive surfaceis disclosed in U.S. Pat. No. 5,268,228 (Orr). A double-sidedadhesive-coated tape has fine grooves on one or both sides of the tapeto facilitate air venting to minimize non-contact areas. The grooves inthe tape are fine enough that, once the two surfaces to be bonded are inposition, the grooves largely or completely disappear. Example 1describes scribing lines through a protective sheet that placed grooves70-150 μm deep in the underlying adhesive surface.).

Good pressure sensitive adhesives for image graphics are available onimage graphic films by 3M of St. Paul, Minn., USA. Pressure sensitiveadhesives having this utility are disclosed in a variety of patents.Representative examples of patents describing such materials includeU.S. Pat. Nos. 5,296,277 and 5,362,516 (both Wilson et al.) and U.S.Pat. No. 5,141,790 (Calhoun et al.). These patents disclose how theadhesive's topography is built from the interface between the adhesiveand the release liner. The principal topographical features in theadhesive surface are isolated protrusions from the adhesive surface withidentified contact areas.

SUMMARY

The art needs films having air egress, tack control, or both, with lesscomplicated manufacturing techniques. In some of the embodimentsdescribed herein, tack control and air egress are provided by a singlemechanical feature: filaments, which are partially disposed in theadhesive layer of an adhesive-backed film in such a way that portions ofthem sit proud from the major adhesive surface, holding the adhesivelayer out, away from an installation surface somewhat, thus providingtackiness (until the presence of intentional application pressure, asfrom a squeegee or other application device). The filaments alsointroduce channels for air or fluid egress into the adhesive layer.

An installer of graphic film as described herein upon a wall may takeadvantage of the tack control by positioning and repositioning thegraphic film until it is just right, then may use a squeegee, hand, orother pressure device to push the film further onto the applicationsurface, working air or fluid bubbles out to the edges of the film viaegress pathways provided by the filaments. In some embodiments, thefilaments are hot melt adhesive, such that an installation techniquethat involves heat may improve the bonding of the graphic film to thesubstrate.

In some embodiments, such films have simplified manufacturing, becausethey may eliminate the need for distinct manufacturing techniquesrelated to air egress and tack control features. In some embodiments, asfor example where the filaments comprise hot melt adhesive, theresultant bond between the graphic film and the installation surface,after installation in the presence of heat, is improved.

Air egress and repositionability are desirable features for someadhesive backed graphic films, allowing an installer to reposition thegraphic on a surface multiple times until the positioning is acceptable,and then allowing the installer to remove air or fluid pockets with theuse of a or other application device. Such features may be facilitatedthrough the build-up of such graphic films on a suitable liner, asdescribed herein.

In one embodiment, thermoplastic filaments are pressed into a releaseliner, such that some of the filaments extend past the major surface ofthe release liner. The adhesive side of an adhesive backed filmcontacted to the filament-containing release liner, such that theadhesive layer bonds to and encompassing portions of the filamentsextending past the major surface of the release liner. When the releaseliner is removed, the resultant structure is an adhesive-backed filmwherein the adhesive layer includes portions of filaments embeddedtherein. These filaments, in various embodiments, serve to hold theadhesive layer up, away from an installation surface (facilitating tackcontrol, which assists may translate to repositionability), and alsocreate channels on either side of the filament (facilitating air orfluid egress). Particular embodiments may be generated that are tuned toone of these features or the other.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a drawing of a liner having partially embedded filamentsdisposed thereon.

FIG. 1B is a drawing of a liner having partially embedded filamentsdisposed thereon.

FIG. 1C is a drawing of a liner having partially embedded filamentsdisposed thereon.

FIG. 1C′ is a zoom in on a portion of the liner shown in FIG. 1C.

FIG. 1D is a drawing of a liner having partially embedded filamentsdisposed thereon.

FIG. 1D′ is a zoom in on a portion of the liner shown in FIG. 1D.

FIG. 1E is a drawing of a liner having partially embedded filamentsdisposed thereon.

FIG. 1E′ is a zoom in on a portion of the liner shown in FIG. 1E.

FIG. 2 is a drawing of a liner having partially embedded filamentsdisposed thereon, in profile view.

FIG. 3 is a drawing of a liner having partially embedded filamentsdisposed thereon, and an adhesive layer enveloping or partiallyenveloping the non-embedded portions of the filaments.

FIG. 4 is a drawing of a liner stack.

FIG. 5 is a drawing of an adhesive layer having partially embeddedfilaments.

FIG. 6 is a drawing of a film stack on top of an adhesive layer havingpartially embedded filaments.

FIG. 7 is a drawing of an adhesive-backed film as pressed against aninstallation surface, with filaments partially embedded in the adhesivelayer creating air or fluid pathways on the sides of some of thefilaments.

FIG. 8A is a drawing of a manufacturing process for a web havingpartially embedded filaments.

FIG. 8B is a drawing of a manufacturing process for a web havingpartially embedded filaments.

FIG. 9 is a drawing of a machine that can draw filaments to anappropriate average cross-section dimension.

DETAILED DESCRIPTION

Graphic films, as may often be seen containing commercial advertisingcontent, when installed on installation substrate (such as walls,vehicles, boats, semi-trucks, etc.), are typically installed as follows:A film having an adhesive coating on one major side thereof (with a thinsacrificial liner film to protect the adhesive layer untilinstallation), may first be printed with content of choice, thusproducing a graphic film. In the art, this film is may be called abacking. An overlaminate protective layer, or a protective clear coat,may then be applied over the printed side. These steps typically takeplace at a graphic sign shop. When the graphic film is ready to beinstalled, the graphic film is taken to the installation site, which maybe a wall, floor, or any suitable surface, where the installer removesportions of the liner. Depending on the installation specifics and thesize of the graphic film, the installer may remove the whole liner, ormerely pull back the liner a certain parts, exposing the adhesive layer.The installer then loosely positions the graphic film upon thesubstrate, often times iteratively getting the positioning just right,by lifting, positionally adjusting, then re-setting the graphic filmagainst the substrate. When the installer is satisfied with thepositioning, while the graphic film is still relatively loosely tackedto the wall, he may use a squeegee or other pressure producing device topress the loosely tacked areas of adhesive-backed graphic film onto theinstallation surface. Further portions of the liner are then removed,and the graphic film further pressed onto the installation surface. Allthe while, the installer is careful to minimize air or fluid bubbles(depending on the characteristics of the film to be installed, thesurface or adhesive is sprayed with detergent and water, which can aidin the installation process). If bubbles do occur, the installer worksthem to the edge with his squeegee, or he may lance them with needle orsharp knife.

Graphic films known in the art and suitable for such an installationhave been engineered to include features that provide for enhanced fluidegress and tack control. Regarding fluid egress, such features oftenexist by way of channels formed into the adhesive layer itself, bymethodologies known in the art, but often involving embossing a raisedpattern into the liner, which serves to structure the adhesive layer,introducing a network of channels by which fluid may egress. With regardto tack control, there are a number of approaches taken in the art, mostof which involve the presence of material or mechanical features, e.g.bumps, sometimes made of ceramic material, designed to prevent theadhesive layer from aggressively adhering to the installation substrateexcept in the presence of intentional pressure as from an installer. Forexample, an array of small raised non-adhesive pegs disposed on theadhesive layer may provide good tack control.

The problems of air bubble formation and fluid egress problems are wellunderstood in association with large format graphics, but these problemsalso exist for small graphics, decals, and other adhesive backedarticles, where speed of application is important for economic ormanufacturing reasons.

A new way to provide for fluid egress and tack control has beendiscovered. The new method and article involves the provisioning offluid and air egress, as well as tack control, through the use of long,thin filament pieces embedded in an adhesive layer of an adhesive backedfilm. This newly discovered approach has the potential to providebenefits in terms of manufacturing costs, while providing good fieldperformance. In one embodiment, this new construction may avoid orminimize manufacturing complexities associated with structuring theadhesive layer using an embossed liner, an approached used in the priorart. In various embodiments, the newly discovered process and articlealso only requires one mechanical structure (the partially embeddedfilaments) to provide both fluid egress and tack control.

FIG. 1A is a rendering of a filament-containing release liner 10Aincluding release liner 12A having filaments 15 pressed into the surfacethereof. In the embodiment shown, there is not yet an adhesive layer,which will later be applied as a layer, enveloping or partiallyenveloping the filaments, to the extent that they sit proud of the majorsurface of release liner 12A.

Release liner 12A is a film intended to be utilized as liner stock inconjunction with protecting the adhesive part of an adhesive backedfilm. Release liner 12A may be any suitable type of liner material; insome embodiments it may comprise a paper or plastic-based film, whichdepending on application may be coated with a material (such as asilicone-based material) that prevents an adhesive, as from anadhesive-backed film, from overly aggressively adhering from itssurface. Release liners are designed to facilitate manufacturing of anadhesive-backed film, and protect said adhesive backing from the time ofmanufacture until installation. At installation time, the release lineris typically removed from the adhesive backed film and discarded orrecycled. Release liners may comprise many different materials known inthe art, including for example, paper, polyester, or HDPE filmsubstrates.

Filaments 15 are long, thin (high aspect ratio) fiber strands, havingaverage cross section dimension of 50 μm or less. In some embodimentsthey may extend for very long runs, particularly down-web. In otherembodiments, the filaments are filament pieces, for example between 10and 50 mm, though other sized pieces are possible. The filaments arenipped or otherwise pressed into the surface liner 12A, as will befurther discussed later in this disclosure. Larger cross sections arepossible and contemplated within the scope of this disclosure, but asthe filaments become larger, it may be more difficult to hide theirappearance on a finished graphic article, depending on thecharacteristics of the adhesive layer and other substrates. In oneembodiment, the filaments 15 comprise thermoplastic extrusions, and in afurther embodiment they comprise a thermoplastic resin that may melt attemperatures between about 115° C. and 171° C. (or even as high as 200°C. or higher, or as low as 100° C. or lower). Filaments could be madeout of a thermoplastic-thermoset material that cures upon extrusion;they could also be made of UV curable materials.

Liner 12A has a total area “T”, a first area “A” that is the area of the“lands” or filaments 15A when viewed from a plan perspective. In someembodiments, there may be hundreds or even thousands or hundreds ofthousands of filaments on a liner. The ratio of A to T for non-thermosetadhesive filaments may be from 5-99%, more preferably from 5 to 50%; inour experiments a ratio providing good performance characteristics ofegress and controlled tack in a graphic film application, withoutsignificant degradation of adhesion, is between about 5% and 15%. If thefilaments are heat activated, thermoset adhesive strands, however the Ato T ratio can be much higher and still provide adequate adhesion andeven improved adhesion when compared with non-heat activated filaments.For example, with heat activated adhesive filaments, the A to T ratiomight be 10-50% and provide good air egress and adequate tack control,and even better adhesion after application (as compared with a non-heatactivated adhesive filament). Of course, the heat activated adhesivefilament embodiments could use much higher A to T ratios as needed,possibly at ratios the way up to 90%, and possible more. A higher A to Tratio will result in lower tack (to some degree this corresponds withimproved repositionability), improved air egress, but worse initialadhesion.

All of these values are average values, and exemplary only—certainembodiments of the methods described herein have high variability—forexample, the filaments in fact overlap in some places, and the filamentsthemselves may be broken or not pressed into the surface of liner 12 atsome places (hence in reference to FIG. 2, which is an end view of aportion of liner 12A shown in FIG. 1 (and as specified “2” in FIG. 1),filaments 15 are shown extending into surface 17 of liner 12 to variousdegrees—some are almost fully extended into surface 17; others do notextend in at all). At 300 μm spacing, and 50 μm diameter, the A to T isabout 15%. In some embodiments, as mentioned, A to T may be greater thanor equal to 15%, but other percentages are suitable for differentapplications, as will be appreciated upon further review of thisdisclosure.

As mentioned, filaments 15 may be pressed into release liner 12 per aroll-to-roll manufacturing operation. Most commonly this is done via anip. Generally, the filaments in are applied in a down-web direction,resulting in a down-web orientation, though in some embodiments asubstantial cross-web effect may be introduced by various techniquesknown in the art (e.g., moving the release liner web or die side-to-sideas the filaments are introduced onto the surface of the release liner,or blowing partially oriented fiber pieces at different angles onto theliner). Filaments 15 are generally manufactured by way of extrusion,then drawn to a desired average cross-section before being pressed intothe surface of release liner 12, as will be discussed further in thisdisclosure.

Filaments 15 may be very long and continuous (unbroken) along extendedportions of the web, or they may be broken, either intentionally, aswill be discussed in conjunction with some embodiments, or as a resultof manufacturing process variability. Filaments 15 in one embodiment areuniformly distributed across the web, in one embodiment covering about15% of the surface area of the web, as mentioned earlier. Filaments 15may be generally linear, having a dimensionality generally down-web (asis shown in the embodiment associated with FIG. 1A, or they may embody asinusoidal or zig-zag pattern (see FIG. 1E), or such patterns may becombined. Sinusoidal or zig-zag patterns may be introduced to the web bycross-web oscillation of the web or the installation die. Such patternsmay have a period of anywhere from 25 to 50 mm or more (or less) in thedown-web direction. FIG. 1E is a rendering of what such a web might looklike. Release liner with partially embedded filaments 10E is shown ascomprising release liner 12E and a plurality of filaments contacted to amajor side thereof. FIG. 1E′ is a close up of a portion of the liner,and shows filaments 3A and 3B have a rough sinusoidal pattern, resultingin the filaments overlapping at various points. Such overlap effectscross-web air and fluid egress, as will be seen.

Cross web filaments, oriented orthogonally relative to the down-webfilaments (other orientations that are more or less than 90 degreesdifferent area also possible), may also be placed on top of (or onbottom of) the down-web oriented filaments, as will be described furtherin one of the examples below. FIG. 1D shows a rendering of what such anembodiment would look like. Release liner having partially embeddedfilaments 10D comprises release liner 12D contacted with a pluralityfilaments comprising two sets of filaments, oriented generallyorthogonally to each other. For example, in FIG. 1D′, filament 4B(associated with a down-web direction) is shown as overlapping orunderlapping and orthogonally extending across filament 4A, which isassociated with a cross-web direction. Filaments 15 in one embodimentcomprise thermoplastic extrusions. In one embodiment, the thermoplasticextrusions have a melt index value of 1-500, measured according to ASTMD1238.

Filaments may also be filament pieces or fragments, straight or crimped,available from 3^(rd) party manufacturers, such as T262 1.3 Dtex×12 MMuncrimped core-sheath PES/PBT bicoponent, available from Trevira GmbH ofHattersheim, Germany.

In addition to thermoplastic extrusion, filaments could be produced by aliquid extrusion process. The liquid could be 100% solids (e.g. a UVcurable resin). The liquid could also be a polymer or mix of polymersincluding thermoplastics or thermosets or a combination thereof in asolvent or mixture of solvents such as water, alcohol, ketones, or anysolvent known in the art to dissolve polymers. The liquid could also bean emulsion such as a latex emulsion. The liquid could exit the die andeither exit at the desired diameter or be drawn smaller similar to theextruded filaments. Thereafter the solvent can evaporate, or thematerial can be cured creating a filament useful in this invention.

The cross sectional profile of the filaments 15, as seen in FIG. 2, maybe basically round, or they may be any suitable shape. The pressingoperation may modify the cross-sectional profile, effectively flatteningwhat would be basically round filaments.

The filaments are pressed into a release liner, preferably as part of aroll-to-roll manufacturing operation. The 12 liner may be a releaseliner. Liner 12 can be any suitable release or transfer liner known tothose skilled in the art for use with adhesives and that is capable ofhaving filaments pressed thereon. Nonlimiting examples of liners includea variety of commercial materials from 3M of St. Paul, Minn., and othercommercial manufacturers of liner products such as Rexam ReleaseCorporation of Oakbrook, Ill., Daubert Coated Products of Westchester,Ill., or Loparex of Cary, N.C. Liners are typically polyethylene coatedpapers with commercial silicone release coatings; polyethylene coatedpoly(ethylene terephthalate) films with commercial silicone releasecoatings; or cast polypropylene films which can be embossed withpattern(s) while making such films, and thereafter coated withcommercial silicone release coatings. Additional useful liners areidentified in the Calhoun et al. and Wilson et al. patents, referencedabove.

Generally, the filaments should be harder than the release liner duringthe pressing, such that the filaments will be at least partially pressedinto the surface of the release liner (e.g., the liner material willdeform somewhat to accommodate the pressed filaments). The release linermay be heated to a softening point to effect this appropriate variationin hardness. In some embodiments, the filaments are, at typicalprocessing temperatures, already harder than the release liner so maynot be necessary to effect further softening of the release liner.

FIG. 2 is an end view of release liner 10, as per view “2” in FIG. 1A(or as per similar views associated with embodiments shown in FIGS.1B-1E). Filaments 15 are seen to be distributed across surface 17 ofliner 12. From left to right, individual filaments may be seen to bepartially embedded into release liner 12, with only a portion of thefilament extending outward from the major plane of surface 17. Somefilaments, at any given cross-section, may be 0%, 10%, 20%, 30%, 40%,50%, 60%, 70%, 80%, or even 90% or more enveloped within liner 12. Thesame filament may be enveloped a different percentage at a differentcross-section (upweb or downweb). Thus the filaments exhibit variabilityregarding how much they are embedded within the liner 12, or conversely,how much they protrude from major surface 17 of liner 12. In somepreferred embodiments, 80-100% of the filaments, in cross section,extend below the surface 17 of liner 12; thus the other 0 to 20% of thefilaments will protrude above (e.g., sit proud of) surface 17.Generally, for filaments having an average cross-sectional width of 15μm, the filaments will be >3 μm, preferably >5 μm, and even morepreferably >10 μm embedded into the liner, on average.

FIG. 3 is the cross sectional rendering of the release liner shown inFIG. 2, additionally including a further adhesive layer 20. After thefilaments 15 are pressed into liner 12, an adhesive is disposed onto thefilament-containing side of liner 12. The adhesive may be so disposed bytechniques known in the art, including liquid coating (and subsequent UVcuring), or by lamination wherein an adhesive or an adhesive backedliner is pressed onto the filament-containing side of the liner 12 asboth materials pass through a nip. Other ways of disposing an adhesivelayer onto the filament-containing side of liner 12 will be apparent tothose skilled in the art. The adhesive may be any suitable pressuresensitive adhesive. Nonlimiting examples of pressure sensitive adhesivesinclude those disclosed in U.S. Pat. No. 4,994.322 (Delgado et al.);U.S. Pat. No. 4,968,562 (Delgado); EPO Publication 0 570 515; EPOPublication 0 617 798; pressure sensitive adhesives disclosed in U.S.Pat. Nos. 5,296,277 and 5,362,516 (both Wilson et al.) and U.S. Pat. No.5,141,790 (Calhoun et al.) and PCT Patent Application Serial No. WOUS96/1687 (Keller at al.), and any other type of pressure sensitiveadhesive disclosed in Satas, et al., Handbook of Pressure SensitiveAdhesives, 2nd Ed. (Von Nostrand Reinhold) N.Y., 1989).

Suitable choices may include tackified rubbers, acrylates,methacrylates, etc. Manufacturing process variability may jostle thefilaments and liner somewhat before adhesive is applied, causing someportions of a given filament, when viewed in cross section, to bepositioned fully proud of the surface of liner 12, and thus fullyencompassed within the adhesive layer 20. Of course, other filamentsremain partially embedded within liner 12, and thereby have portionsthat are not exposed to adhesive layer 20. As mentioned in reference toFIG. 2, filaments are preferably partially embedded in the liner, suchthat the adhesive coating may envelop only the portion of the filamentnot embedded in the liner. In practice, if filaments on average have adiameter (or height) of 15 μm, the filaments may extend on average about80-100%, or 12-15 μm into the surface of liner 12, allowing theremaining portion of the filament (0-20%, or about 0-3 μm) to protrudefrom surface 17 and thereby be encompassed by adhesive layer 20. Asmentioned, given the sheer volume of filaments and process variability,the actual depth to which the filaments may be embedded will vary, withsome filaments not being at all embedded, and others being almost fullyembedded.

In one embodiment, filaments have a cross section or diameter that issmaller than the thickness of the adhesive layer 20, such that evenfilaments that sit fully proud of surface 17 may be fully encompassed byadhesive layer 20. Returning briefly to FIG. 1 and the percentage of Ato T—it may now be appreciated that once the liner 12 is removed fromadhesive layer 20, the filaments 15 will stick to adhesive layer 20 andthereby create a series of filaments on the surface of adhesive layer20. Most of the filaments, in one embodiment, will have diameters thatextend 80% or more, in cross section, above the surface of adhesivelayer 20. When the non-filament containing side of adhesive layer 20interfaces with a graphic layer (e.g., a printed graphic to be installedon a surface), as is one example of a contemplated application of theconstruction thus described, these filaments serve at least two purposesduring the installation of said graphic layer on a surface: (1) theyhold the adhesive layer away from the surface somewhat, promotingrepositionability of the graphic layer on an application surface; and(2) fluid egress (e.g., driving air or liquid bubbles to the sides ofsuch graphic layer, with a hand or squeegee, so they might escape fromunder the graphic layer. If the thermoplastic extrusions comprise ahot-melt adhesive, once the graphic has been properly positioned withbubbles removed, the graphic hot-melt adhesive may be activated, forexample by using a heat gun or torch or other heating device, thuspromoting improved adhesion and also flattening the filaments. Asmentioned in reference to FIG. 1, one A to T ratio of about 15% has beenseen to work satisfactorily for air egress and repositionability whenusing 15 μm average diameter filaments (which extend 80-100%, e.g.,12-15 μm, into the surface of liner 12). However, a higher A to T ratiowill result in better repositionability and egress, at the expense ofadhesion from the pressure sensitive adhesive. If the filaments comprisehot melt adhesive, i.e., the ultimate adhesive qualities are to beenhanced by a final heating step anyway, the performance of the pressuresensitive adhesive may not be as critical. However, a lower A to T maybe desirable when the filaments do not comprise a hot melt adhesive, andthe pressure sensitive adhesive is to be relied on as the primaryadhesive mechanism. The A to T ratio can be higher than 15% and stillprovide good repositionability and air egress (while improvingadhesion)—ratios of 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%,70%, 75%, 80%, and even higher may be suitable for some applications,with the higher levels more particularly suited to embodiments where thefilaments comprise hot melt adhesives which are activated by introducingheat, as from a heat gun, during the installation process. Conversely,ratios less than 15%, including 10% or even 5% may be desirable for someapplications.

Adhesives can be selected from a variety of conventional adhesiveformulations. Nonlimiting examples of adhesives include pressuresensitive adhesives, hot melt or heat activated adhesives that arepressure sensitive at the time of application such as pressure sensitiveadhesives disclosed in U.S. Pat. No. 4,994,322 (Delgado et al.); U.S.Pat. No. 4,968,562 (Delgado); EPO Publication 0 570 515; EPO Publication0 617 708; pressure sensitive adhesives disclosed in U.S. Pat. Nos.5,296,277 and 5,362,516 (both Wilson et al.) and U.S. Pat. No. 5,141,790(Calhoun et al.) and U.S. patent application Ser. No. 08/559,037 (Kelleret al.), all incorporated by reference and any other type of pressuresensitive adhesive disclosed in Satas, et al., Handbook of PressureSensitive Adhesives, 2nd Ed. (Von Nostrand Reinhold, N.Y., 1989), thedisclosure of which is incorporated by reference.

FIG. 4 is the cross sectional rendering of the release liner shown inFIG. 3, but additionally including paper backing 25. In such aconstruction, paper backing 25 would support a polyethylene film (liner12), the top side of which (that is, the side interfacing with adhesivelayer 20) would be coated with a release agent of some sort (oftensilicone-based). While liner 12 and paper backing 25 are shown separatein FIG. 4, in practice a reference to “release liner” may comprise thepaper backing (if present), the polyethylene liner layer 12, and therelease agent (if present).

FIG. 5 is a cross sectional rendering of the adhesive layer andfilaments shown in earlier figures, but now with liner 12 removed. Thefilaments 15 extending into the surface of liner 12 were protected fromadhesive layer 20, and now, to the extent they were enveloped in liner12, they sit proud of major adhesive surface plane 19. Such portions ofsuch filaments do not contain adhesive.

FIG. 6 is a cross-sectional rendering of the adhesive layer andfilaments, with liner removed (as in FIG. 5), but additionally includinga number of further layers as might typically be seen in a fieldapplication of a graphic. Adhesive layer 20 is coupled to film 30. Film30 may be any suitable film, such as PVC-based films, or polyolefinfilms, or thermoplastic polyurethane and cellulose ester films asdescribed in US Patent Application Publication Nos. 2014/0141214“Graphic Article” (Steelman and Lyon) and 2014/014009 “Graphic Article”(also Steelman and Lyon). Film 30 may also comprise films useful forcontact with adhesive surfaces including Controltac™ branded filmscommercially available from 3M, films disclosed in U.S. Pat. No.5,721,086, foils, metallic plates, ceramic plates, polymeric sheets,vibration damping materials, reflective sheeting, retroreflectivesheeting, top-coated materials, industrial tape backings, hypoallergenictape backings, and combinations thereof.

The upper surface of film 30 may be printed with text, images, graphics,advertising, etc. In some embodiments, a liner (e.g., liner 12 fromearlier described embodiments), along with the filaments and adhesivelayer and the film layer 30, are sold by sheet or roll for printing orother use, and further layers, such as further adhesive layer 40,overlaminate 50, and clear coat layer 60 are (optionally) added layer.

Any suitable film can comprise film 30, which is contacted to the majorsurface of adhesive opposite the major surface(s) of adhesive havingfilaments extending from the surface thereof. Because the film islaminated to adhesive after the adhesive is applied to thefilament-containing liner, the appearance of any exposed major surfaceof film 30 is not generally adversely affected by the topography of thefilaments. With that advantage, film 30 can be imaged using anycommercial technique, including electrography, inkjet, screen printing,flexography, electronic cutting, or other imaging or graphic techniques.

FIG. 7 is a cross-sectional rendering applied film article 51, whichcomprises film 30 applied to substrate 200. Substrate 200 may be, forexample, a wall in a commercial establishment, and the upper majorsurface of film 30 may be printed with graphics. An applicationtechnician may remove liner 12 (as in FIGS. 2, 3, 4), exposing filamentcontaining adhesive layer 20. The technician may then gently bring theadhesive-and-filament exposed film (e.g., the stack that comprisesfilaments 15, adhesive layer, and film 30 (and any further films orlayers as exemplified in the embodiment shown in FIG. 6)) into contactwith the application surface of the wall. The filaments hold theadhesive layer away from the application surface of substrate 200,promoting repositionability, that is, the ability of the technician totack up the graphic film and then remove it to change its position. Whenthe graphic is properly positioned, the technician may more firmly pressthe filament containing adhesive layer 20 into the substrate, promotingmore intimate contact between the adhesive layer 20 and the surface ofsubstrate 200. Air or fluid egress channels, or conduits, 14 are formedin areas adjacent to filaments 15. The technician, with aid of asqueegee or similar device, may then push any developed air pockets (orfluid pockets if a water or solvent mixture is used in the applicationprocess) for egress at the periphery of the film article. Such fluidegress is facilitated by the filament channels that may exist on eitherside of filament 15.

After application, if the filaments comprise hot melt adhesive or heatactivated material, the technician may use a heat gun or other heatsource to heat up the filaments and then use a roller or otherapplication device to further press film onto the surface of substrate200. In the process, the filaments are flattened and/or the adhesion isactivated so as to promote further adhesion.

In many film article applications that involve printed graphics, linear,generally down-web, air egress is acceptable. In some cases, however, itmay be preferred to have cross-web air egress also. Cross-web egress canbe achieved in a number of ways. In one example, a zig-zag or sinusoidalpattern may be introduced to the down-web filaments, providing cross-webpathways (as seen in FIG. 1E). In another embodiment, cross-web sectionsof the filaments can be laser ablated and/or melted. For example, a 0.25to 5 mm section of the filaments, across the whole web, could be ablatedat a pitch of 12 mm or more. In one embodiment, ablation removes a 5 mmgap at a 12 mm pitch. FIG. 1B shows a rendering of what such anembodiment would look like. Release liner having partially embeddedfilaments 10B comprises release liner 12B contacted with partiallyembedded filaments 15B. The filaments have a directionality associatedwith the down-web direction of the web. Areas between the filaments havebeen ablated at a regular pitch, creating the look of cross-web stripes,alternating between sections of filament-containing material andsections devoid of filament containing material. These cross-websections promote cross-web air egress in a finished article.

In another example, the filaments can be embossed in a periodic manner.The embossing will preferably reduce the height of the filament by50-90% to allow fluid to egress cross-web. This embossing will alsoprovide for cross-web air egress, and the emboss length and frequencyare similar to the laser ablation method previously described. Thefilaments are embossed in one embodiment before they are pressed intothe liner. In another embodiment, the full filaments are pressed intothe liner, then the filaments and the liner are embossed. In eithercase, the result is cross-web patterns in the filaments, where theheight of the filaments has been effectively reduced by pressing thefilament portions.

FIG. 8A is a schematic of a manufacturing process for a liner havingfilaments pressed therein, which may then be contacted with (e.g.,coated) with an adhesive layer and printed films, as described above.The process shown in FIG. 8 is a roll-to-roll process, with filmconveyed left to right. Other manufacturing processes are also possible,as will be evident to one skilled in the art having read thisdisclosure. A plurality of filaments 170 are extruded from extruder 150,onto chill roll 120. If the filaments as extruded are not at optimaldiameter, as an intermediate step they may be pulled to proper diameteron a roll before they are disposed onto the liner, as is shown in FIG.9, which shows the extruder 150 extruding filaments 170 onto chilledroll 125 that is turning faster than the rate of extrusion, as part of amelt-drawn process, thereby stretching the filaments. Roll 110 and roll120 (which is optionally a chilled roll), bring liner 140 and filaments170 together at nip 115, thereby pressing the filaments into the surfaceof liner 140 and creating filament containing liner 140 a. Roll 130 thenorients filament-containing liner 140 a for further processing, asneeded. For example, such further processing might include coating thefilament containing liner 140 with an adhesive layer and a film, such asadhesive layer 20 and film 30 (shown in, e.g., FIG. 6). In such anembodiment, the non-adhesive interfacing major surface of film 30 mightbe ready to be shipped to a print shop to be used as stock for printinggraphics. As shown in FIG. 8, however, the filament-containing liner 140a is rolled on roller 180. Once rolled, filament-containing liner 140 amay be stored for further processing later.

The embodiment shown in FIG. 8a also includes laser 160, which may beused to ablate portions of filaments 170 before they are pressed intoliner 140 (see FIG. 1B). Such ablations may be cross-web, facilitatingcross-web fluid egress. The laser may be an infra-red laser, nearinfrared laser, or ultraviolet laser. It may be pulsed or continuous. Itwill generally be delivered into a scanner having mirrors that willdeliver the laser to the roll onto which the filaments are beingdisposed. The scanner's mirrors will direct the laser from one edge ofthe web to the other. If the web is too wide, multiple scanners may beused with one laser or multiple lasers to accomplish this task.

In another manufacturing embodiment, filament sections of appropriateaverage size (e.g., 5-50 mm) are blown onto a heated liner before beingpressed thereinto. FIG. 8B shows blown filament apparatus 201. Hopper210 is loaded with fibers of appropriate dimension. Feed roll 203 pullsfibers from the hopper and into teeth of lickerin roll 200. Forced air205, preferably heated, dislodges the fibers from lickerin roll 200 anddeposits the filament pieces onto a major surface of a liner 207, whichmay be heated to the point of being slightly tacky. At the bottom of thehopper, there could be a knurled or otherwise textured roll (not shownin FIG. 8B) that would rotate, and if necessary, further open thefilaments preferably individualizing them. The filaments may then bepressed into the major surface of the liner with a nip (not shown inFIG. 8B). Increasing the distance the blown filaments travel beforeencountering the web, or increasing the air flow can decrease thedimensionality associated with the deposited filament piece (effectivelyincreasing the “randomness” of the filaments as deposited on the liner).In a further alternative embodiment of such a filament blowing system,two fiber blowing systems may be used: one at 45° to the downwebdirection and one at 45° to the cross-web direction, such that theresulting set of filaments tend toward orthogonal orientation on theliner surface (and thus effecting air or fluid egress in two in afinished article). FIG. 1C shows a resulting release liner—release linerwith partially embedded filaments 10C comprises release liner 12C withfilament pieces disposed thereon. The filament pieces comprise twodifferent sets based on their orientation. A first set is disposed suchthat they are generally oriented with direction A; the second set isdisposed such that they are generally oriented with direction B.Direction A and B differ by 90° (other differences are possible andcontemplated within this disclosure). In FIG. 1C′, a zoom in on aportion of the liner shown in FIG. 1C, individual filament pieces 4A maybe seen disposed approximately orthogonal to filament pieces 4B.

In yet another manufacturing embodiment, filaments can be introduceddirectly to the adhesive layer of an adhesive-backed film. Such amanufacturing process would like similar to that shown in in relation toFIG. 8B, except liner 207 would be an adhesive coated film, adhesiveside up. After coating a film with an adhesive layer using knownmethods, filament pieces are disposed directly onto the adhesivecoating, with forced air 205 being cooled as necessary to develop theproper rheology of the adhesive layer, thus preventing the filamentsfrom sinking too far into the adhesive layer. The filaments are thustacked slightly to the adhesive surface. The filaments may settle on theadhesive layer in a general alignment consistent with the direction ofthe air flow; multiple filament deposit stations oriented at two (ormore) angles to the web could effect cross-over of the filaments andultimately cross and down-web air and fluid egress, as discussed inrelation to the above manufacturing embodiment. For example a firststation could be oriented to position filaments at an angle 45° fromdown-web, and a second station could be oriented to position filamentsat an angle −45° from down web.

Once the filaments are on the adhesive layer, the next step is to applya release liner to the adhesive layer (which now contains filamentpieces) in such a way as to let the filaments, in general, remainextending outward from the surface of the adhesive layer, as discussedearlier in this disclosure. Thus, in one setup, the adhesive-coated filmand the filaments are chilled, and a release liner is heated to asoftening point, then both are fed into a nip. The liner could befurther heated as it wraps around the nip roll. This heating softens theliner release layer, and in the nip, the cool adhesive surface withfilaments is contacted to the hot softened liner surface, causing thefilaments to at least partially embed into the liner release layer, theremainder being partially embedded in the adhesive layer. When therelease liner is removed in the field, the portions of the filamentsextending into the release liner would stand proud of the adhesive layerproviding benefits and functionality of the embodiments describedearlier.

Usefulness of the Invention

Image graphic films are unexpectedly improved by the filament containingadhesive surfaces of the present invention. Image graphic films havingfilament-containing adhesive surfaces of the present invention can beused to provide fluid egress for a predetermined period of timeaccording to the rheology of the adhesives (creep compliance, modulus,etc.). They also may effect good tack control properties.

One skilled in the art can control fluid egress but minimize fluidingress at the adhesive interface by (a) selecting a suitable adhesiveand (b) forming an appropriate topography by controlling the diameterand hardness of the filaments, and how much they are pressed into theliner, according to the present invention, and (c) appropriatelyapplying the adhesive to the supporting substrate. This provides airegress during installation but afterwards seals the interface betweenthe adhesive and the supporting substrate.

Alternatively, the skilled artisan may select an adhesive with differentrheological properties to maintain the topography of the adhesivesurface for a longer period of time after initial installation, topermit multiple reinstallations onto the same or different supportingsubstrate or to maximize available routes for fluid egress.

Adhesive surfaces of the present invention improve economic value byreducing manufacturing costs associated with structuring adhesives withchannels, etc., by way of embossing a liner.

Further features, advantages, and embodiments are described in theexamples.

EXAMPLES

Webs with partially embedded filaments were prepared. The resultantarticles provided good tack control (facilitating repositionability) andair release, as shown in the following examples. These examples are forillustrative purposes only and are not meant to limiting the scope ofthis disclosure.

Materials:

Abbreviation: Description

R1: Polypropylene resin pellets available from Total Petrochemicals &Refining USA, Inc., Houston, Tex. as 3860.

L1: Release liner available from Loparex LLC, Cary, N.C. asC2S4212A/4000D L/H PC SKC CL PET.

F1: Reflective Graphic Film available from 3M Company, St. Paul, Minn.as 3M SCOTCHLITE Reflective Graphic Film IJ5100.

ADH 1: Hot melt adhesive available from FPC, Wauconda, Ill. asSUREBONDER 725R4-1-GP glue sticks.

T1: Double Sided Tape available from 3M Company, St. Paul, Minn., asSCOTCH Double Sided Tape 665 ½ in.

F2: Transfer adhesive available from 3M Company, St. Paul, Minn., as9415 High/Low Tack Double Coated Tape

Example 1: Liner with Partially Embedded Filaments

Liner L1 with release surface facing up was fed through a heated nipconsisting of a rubber roll (Roll 1) on top and a steel roll (Roll 2) onthe bottom at 60 feet/minute. The nip pressure was 40 lb./in. The nipheat exchanger for both rolls was set to set to 240° F. (116° C.), andthe exiting liner was estimated to be 206° F. with an infraredthermometer. Resin R1 was heated and extruded at 480° F. (249° C.) in anextruder with a screw diameter of 50 mm and L/D of approximately 32:1through a 2-in die with 60 orifices per in onto a room temperature steelroll (Roll 3). The drilled die orifices had openings of 0.008 in (0.20mm). The extrusion rates were measured at an average of 0.14 lb/hr, butvaried due to running low extruder rates.

The resulting extruded filaments were drawn over 5 in. and touched theside of the smooth steel roll (Roll 3) before being nipped with theheated liner on the heated roll (Roll 2), thus pressing the extrudedfilaments into the up-facing side of the liner. A significant number offilaments “twinned” or merged together near the die tip, and there wasat times non-uniform rates of filament extrusion due to theaforementioned variable rate and some variable accumulation on the dietip.

The filaments were then nipped setting the gap to 2 mil with the heatedliner between Rolls 2 and 3, thus embedding the filaments into the linersurface. The majority of the filaments were 28-30 μm in height, but dueto filaments combining or “twinning” and the aforementioned variablerates, the filament width ranged between 17 and 155 μm. This produced aliner with embedded filaments.

Example 2: Film Laminated to Liner with Embedded Filaments

A section of liner with embedded filaments, a la Example 1, was placedon a hard, flat bench surface with the embedded filaments facing up. Aslightly larger section of reflective graphic film F1 was then laminatedto the liner: First, a small section of film F1 was aligned with thefilament containing liner and manually tacked to the bench. Then, arubber roller (similar to p/n EDI: 19560, available from MarshalltownCompany, Marshalltown, Iowa) was placed on the tacked portion of thefilm F1 and advanced, thus laminating the film F1 to the Liner withEmbedded Filaments.

Example 3: Repositionable Adhesive Film with Filaments

The laminate of Example 2 was separated manually removing the liner L1used Example 1 from the film F1. As the two films separated, thefilaments remained on the adhesive side of the film F1. This formed anadhesive backed film with partially embedded filaments.

The adhesive backed film with partially embedded filaments was placedadhesive side down onto a surface, without additional pressure—that is,there was no aggressive pressing, such that the filaments prevented theadhesive layer from making intimate contact with the surface. Theadhesive backed film with partially embedded filaments was then movedand repositioned by pulling a corner of the film. Once the film waspressed gently, it adhered to the surface. When pressed more firmly moreadhesive bonded to the surface, increasing the bond.

Another sample (this one a 1.5 inch wide strip) of adhesive backed filmwith partially embedded filaments was adhered to a glass surface bypressing and advancing a hand-held roller (similar to p/n EDI: 19560,available from Marshalltown Company, Marshalltown, Iowa) across itssurface while applying approximately 100N downward force. This actionsmoothed out the top surface, adhered the adhesive to the glass surface(approximately 97% adhesive contact was observed from the back side ofthe glass), and removed most of the remaining air, thus creating a goodbond.

Example 4: Adhesive Backed Film with Partially Embedded Hot MeltAdhesive Filaments

A filament alignment tool was constructed for pressing filaments into aliner. It comprised a flat rectangular plate with an array of pegs alongtwo opposite sides (0.039 in (1 mm) pegs with 0.079 in (2 mm)center-to-center pitch).

An adhesive-backed reflective graphic film F1 sample approximately 4in×4 in was placed in the center of the alignment tool with linerremoved, adhesive side facing up. A black poster board surface was seton a bench. A glue stick of ADH1 was placed in a 3M POLYGUN AE II (3MCompany, St. Paul, Minn.) and heated according to directions. Hot meltadhesive filaments were manually created using the followingprocedure: 1) Generally less than 0.01 g of adhesive was extruded ontothe poster board; 2) The gun was lifted approximately 0.13 in (3 mm) offthe poster board creating a filament; 3) The gun was quickly acceleratedparallel to the poster board surface and moved at a velocity greaterthan 10 ft/s (3.0 m/s), drawing the filament, and 4) The hot meltadhesive was tacked to the poster board.

Hot melt adhesive filaments less than 100 microns in average crosssection were selected, manually transported to the alignment tool,aligned against a side of the corresponding pegs in each peg strip, andpressed onto the adhesive surface of the graphic film at approximately 1MM intervals. Overhanging portions of the filaments were severed with arazor.

An approximately 1.5 in wide strip of this sample was applied to a glasssurface by pressing and advancing a hand-held roller (similar to p/nEDI: 19560, available from Marshalltown Company, Marshalltown, Iowa)across its surface while applying approximately 10N downward force,providing light tack. A heat gun (Master Heat Gun, model #HG-301Aavailable from Master Appliance Corporation, Racine, Wis.) was used toraise the film (and filament) temperature to greater than 150° F. Thehand-held roller was advanced across the surface applying approximately100N downward force. This action smoothed out the top surface, moldedthe hot melt adhesive filaments to the glass surface, and removed mostof any trapped air. Upon microscopic analysis, it was evident that therewas little or no air between the filaments and that the filaments haddeformed and adhered to the glass surface. The back side of the glasssurface was observed, and it appeared that nearly 100% of the glasssurface was in contact with the adhesive layer (before the heating andapplication, it was approximately 66%).

Example 5: Adhesive Backed Film with Partially Embedded Filaments HavingCross Web Variation

An approximately 4 in.×2 in. sample of reflective graphic film F1 withthe adhesive side up, was placed on the filament alignment tooldescribed above. Filaments similar to those in Example 1 were placed onthe adhesive surface of reflective graphic film F1. Filaments weredeviated from a linear, parallel path by guiding the filament path usinga sharp tweezer tip, creating an arc in the filament path.

Example 6: Tack Controlled Adhesive Backed Film with Partially EmbeddedFilaments Having Down-Web Variability and Additional Filaments ArrangedPerpendicular to the Down-Web Filaments

Filaments prepared similarly to those in Example 1 were placed atop anadhesive backed film similar to Example 5. Additional filaments wereadded to this array, generally perpendicular to the primary filamentarray. A curve was placed in additional filaments using the method ofExample 5, thus creating a curve in the filaments with an approximately0.13 in (3.3 mm) deviation from a straight line. The filamentsperpendicular to the primary filament array were spaced approximately0.4 in (10 mm) apart. The final array was approximately 4 in.×4 in. Thisproduced an adhesive backed film with filaments having varying down-webdirection and additional filaments arranged perpendicular to thedown-web filaments.

An approximately 1 in.×3 in. strip was cut from this film of Example 6.The film was laid on a glass slide surface, adhesive side down. Anapproximately 0.25 in. (13 mm) section on the left side was pressedagainst the glass, creating a strong bond. The strip was adhered to aglass slide by pressing and advancing a hand-held roller (similar to p/nEDI: 19560, available from Marshalltown Company, Marshalltown, Iowa)across its surface from the right side while applying approximately 100Ndownward force. Trapped air was easily egressed in both cross-web anddown-web directions.

Example 7: Adhesive Backed Film with Partially Embedded and EmbossedFilaments

An approximately 4 in.×4 in. sheet of transfer adhesive F2 was adheredbetween the peg strips in the filament alignment tool described inExample 4. Filaments similar to those produced in Example 1 were placedin the filament alignment tool as in Example 4 above the wires. Thefilaments were cut with a razor just outside the transfer adhesive F2 inlines parallel to the peg strips.

31 gauge (0.009 in or 0.23 mm diameter) copper wires were laidorthogonal to the direction of the filaments, a 0.4 in (10 mm) spacing,on the adhesive side of a sheet of transfer adhesive F2. Filamentssimilar to those produced in Example 2 were laid atop the copper wires.An 8 in×5 in flat metal plate was placed atop the construction andpressed into the filaments and transfer tape with approximately 2 tonsof force for 1 minute at room temperature. The copper wires thusembossed the filaments. The plate was removed and a sheet of reflectivegraphic film F1 was placed above the now embossed filaments, adhesiveside contacting the filaments. The sheet was gently rolled with a handroller so the adhesive backed side of the film F1 could grab theembossed filaments. The graphic film, including the embossed filaments,was removed from the transfer adhesive F2 and the wires. This formed theadhesive backed film with partially embedded and embossed filaments.

An approximately 2 in.×3 in. strip was cut from this film. The materialwas laid on a glass surface. An approximately 0.25 in (13 mm) section onthe left side was pressed against the glass, creating a strong bond. Thestrip was adhered to a glass slide by pressing and advancing a hand-heldroller (similar to p/n EDI: 19560, available from Marshalltown Company,Marshalltown, Iowa) across its surface from the right side whileapplying approximately 100N downward force. The air was easily removedin both the down web and cross web direction.

Example 8: Adhesive Backed Film with Partially Embedded Filaments HavingCross-Web Ablations

Filaments created similarly to those in Example 1 were arranged in thefilament alignment tool as in Example 4, creating a 1 inch (26 fiber)array. The filaments were positioned using double-sided adhesive tape T1and a positioning plate. Then, a 400W Diamond E laser (Diamond E-400available from Coherent, Santa Clara, Calif.) was set to 10 khz, 8%power and scanned perpendicular to the filament direction at 0.5 m/swhile being focused on the filaments. This action ablated a portion ofthe filaments, creating an approximately 0.4 mm gap in the filamentswhere the laser was scanned. Some material also melted and was pooled atthe filament near the ends of the gap. The adhesive side of a graphicfilm could then be pressed into the filaments to pick them up, and thusfacilitate air egress in both the cross web and down web directions, andtack control.

The invention is not limited to the above embodiments, and at least thefollowing embodiments are described:

Embodiment 1. A method of making a film-based article having a pluralityof filaments, comprising: pressing the plurality of filaments into afirst major surface of a release liner to produce a filament-containingrelease liner; and, laminating an adhesive side of an adhesive-backedfilm to the first major surface of the filament-containing releaseliner.

Embodiment 2. The method of embodiment 1, further comprising: before thepressing step, heating the release liner.

Embodiment 3. The method of any of the previous embodiments, wherein thefirst major surface of the release liner comprises a release agent.

Embodiment 4. The method of embodiment 3, wherein the release agent issilicone-based.

Embodiment 5. The method of embodiment any of the previous embodiments,further comprising: extruding the filaments.

Embodiment 6. The method of embodiment any of the previous embodiments,further comprising: drawing the filaments.

Embodiment 7. The method of embodiment 6, wherein the filaments aredrawn until their average cross-section dimension is between about 5 μmand 50 μm.

Embodiment 8. The method of any of the previous embodiments, wherein thetotal area of the first major surface of the release liner is “T”, andwherein the total area of the filaments is “A”, and wherein the ratio ofT to A to between 5 and 50%.

Embodiment 9. The method of embodiment 8, wherein the ratio of T to A isbetween 5-15%.

Embodiment 10. The method of any of the previous embodiments, whereinthe filaments comprise thermoplastic extrusions.

Embodiment 11. The method of any of the previous embodiments, whereinthe filaments comprise long, thin thermoplastic extrusions.

Embodiment 12. The method of any of the previous embodiments, whereinthe filaments comprise hot-melt adhesive.

Embodiment 13. The method of any of the previous embodiments, whereinthe filaments are oriented in a down-web direction.

Embodiment 14. The method of any of the previous embodiments, furthercomprising: contacting filament pieces to the first major surface of therelease liner.

Embodiment 15. The method of any of the previous embodiments, furthercomprising: blowing filament pieces onto the first major surface of therelease liner.

Embodiment 16. The method of any of the previous embodiments, furthercomprising: contacting a first set of partially oriented filament piecesonto the first major surface of the release liner, the filamentspartially oriented according to a first direction; and, contacting asecond set of partially oriented filament pieces onto the first majorsurface of the release liner, the filaments partially oriented accordingto a second direction.

Embodiment 17. The method of embodiment 16, wherein the first directionand the second direction are orthogonal to one another.

Embodiment 18. The method of embodiment 16, wherein filaments of thefirst and second sets of partially oriented filaments overlap oneanother.

Embodiment 19. The method of any of the previous embodiments, furthercomprising: ablating portions of the pressed filaments.

Embodiment 20. The method of embodiments 1-15, further comprising:embossing portions of the pressed filaments.

Embodiment 21. The method of any of the previous embodiments, furthercomprising: embossing a pattern into the filament-containing releaseliner.

Embodiment 22. A method of making a film-based article having aplurality of filament pieces, comprising: contacting the plurality offilament pieces to an adhesive side of an adhesive-coated film toproduce a filament-containing adhesive-coated film; and, laminating arelease liner to the adhesive side of the filament-containingadhesive-coated film.

Embodiment 23. The method of embodiment 22, further comprising: coolingthe adhesive side of the adhesive-coated film before contacting theplurality of filaments.

Embodiment 24. The method of embodiment 22 or 23, further comprising:heating the release liner before the lamination step.

Embodiment 25. The method of embodiment 22-24, wherein the laminationstep partially presses the filament pieces into the adhesive layer.

Embodiment 26. The method of embodiment 22-25, wherein the heatedrelease liner is heated to a softening point, and the lamination stepallows the filaments to be depressed into the surface of the heatedrelease liner.

The invention claimed is:
 1. A method of making a film-based articlehaving a plurality of filaments, comprising: pressing the plurality offilaments into a first major surface of a release liner to produce afilament-containing release liner such that the release liner deforms toaccommodate the pressed filaments; laminating an adhesive side of anadhesive-backed film to the first major surface of thefilament-containing release liner.
 2. The method of claim 1, furthercomprising: before the pressing step, heating the release liner.
 3. Themethod of claim 1, wherein the first major surface of the release linercomprises a release agent.
 4. The method of claim 2, further comprising:extruding the filaments.
 5. The method of claim 4, further comprising:drawing the filaments.
 6. The method of claim 5, wherein the filamentsare drawn until their average cross-section dimension is between about 5μm and 50 μm.
 7. The method of claim 6, wherein the total area of thefirst major surface of the release liner is “T”, and wherein the totalarea of the filaments is “A”, and wherein the ratio of T to A to between5 and 50%.
 8. The method of claim 1, wherein the filaments comprisethermoplastic extrusions.
 9. The method of claim 1, wherein thefilaments comprise hot-melt adhesive.
 10. The method of claim 6, whereinthe filaments are oriented in a down-web direction.
 11. The method ofclaim 1, further comprising: contacting filament pieces to the firstmajor surface of the release liner.
 12. The method of claim 1, furthercomprising: blowing filament pieces onto the first major surface of therelease liner.
 13. The method of claim 1, further comprising: contactinga first set of partially oriented filament pieces onto the first majorsurface of the release liner, the filaments partially oriented accordingto a first direction; contacting a second set of partially orientedfilament pieces onto the first major surface of the release liner, thefilaments partially oriented according to a second direction.
 14. Themethod of claim 13, wherein the first direction and the second directionare orthogonal to one another.
 15. The method of claim 1, furthercomprising: ablating portions of the pressed filaments.
 16. The methodof claim 1, further comprising: embossing portions of the pressedfilaments.
 17. The method of claim 1, further comprising: embossing apattern into the filament-containing release liner.